public static void Main(string[] args)
        {
            // case 1
              Console.WriteLine("Case1**************");
              RectangleCase1 rect = new RectangleCase1 { Height = 5, Width = 10 };

              Console.ForegroundColor = ConsoleColor.Yellow;

              Console.WriteLine("React Are: " + AreaCalculatorCase1.Area(rect));

              rect = new SquareCase1 { Height = 5, Width = 10 };
              Console.WriteLine("Square Are: " + AreaCalculatorCase1.Area(rect));

              Console.ResetColor();
              Console.ReadKey();
        }
 public static int Area(SquareCase1 rect)
 {
     return rect.Height * rect.Width;
 }